This disclosure relates to downhole tools and, more particularly, to tubing anchors and catchers like those used in oil and gas downhole applications.
Downhole applications involving chemical treatment or well monitoring are becoming more popular as the benefits of treatment and monitoring become more well known. Traditionally, the capillary (chemical injection) or electrical monitoring lines used in these applications are banded to the tubing and terminated above a downhole tubing anchor in the wellbore. Because this anchor requires a number of rotations to set it, its use was limited and, when used, the lines risked damage.
New technologies have made it possible to bypass the anchor and position the chemical treatment or well monitoring equipment right at the pump intake. This arrangement increases the efficiency of the treatment, provides more accurate data and, because it often uses a quarter-turn design, makes it much safer to deploy without risking damage to the capillary lines.
One popular quarter-turn design is a downhole capillary injection anchor (“tool”) that can accept a single ¼″ or ⅜″ capillary line through a passageway located inside the tool's outer components. See e.g., US 2014/0305633 & Table 1 below. The 5½″ tool has a full open 2⅞″ tubing, 2.441″ inside diameter (“ID”) that allows an operator to use it with standard 2¼″ rod pumps. However, the tool is limited to a single capillary line.
Other designs make use of a reduced outside diameter (“OD”) that allows room for the capillary or electrical lines to be banded along the outside of the tool. See e.g., U.S. Pat. No. 7,255,172 & 9,157,289). However, the reduced OD is usually accompanied by a similar ID reduction. Normally, 5½″ tools with reduced ODs are built on 2⅜″ mandrels with 2″ or smaller IDs. While these tools allow room for two or three capillary or electrical lines to be banded along the outside of the tool, the ID restriction requires the use of a smaller pump and, therefore, lower production rates. The ID restriction can result from the use of a one-piece cylindrical cone that threads onto a portion of the anchor and engages the slips (usually four in number). For the cone to properly perform its function, the cone typically has a larger outside diameter than the pusher sleeve and is normally threaded onto the anchor.
TABLE 1Bypass Style (Prior Art) Anchor Designs.WeatherfordVariousBlackCapillaryQuarter TurnTechTACGoldInjectionCapillarySlimlineHydraulicAnchorAnchorsAnchorAnchorAnchor TypeAnchorAnchor/Anchor/AnchorOnlyCatcherCatcherOnlySettingJayJayRotationHydrostaticMechanismRotation to Set¼ Turn¼ Turn7-8 Turns*NoneTool4.500″4.500″4.500″4.784″Maximum ODToolN/AN/A3.750″4.000″Reduced ODTool ID2.441″2.441″1.995″2.441″Capillary Size¼″-⅜″¼″-⅜″¼″-⅜″¼″Capillary1   1   3   2   CapacityCapillaryThroughThroughExternalExternalLocationToolToolGas BypassNoNoYesYes*Unsuitable in practice for running capillary lines because of the number or rotations to set.
A need exists for a reduced OD anchor that reduces or eliminates the rotation required to set the tool, maintains the full 2⅞″ tubing ID, can be used as an anchor/catcher, and can accept more (e.g. >3) and larger capillary lines than had previously been possible (e.g. a ⅝″ line).